WASHINGTON--The controversy over Gulf War syndrome is unlikely to die anytime soon: Several studies released at a press conference here today suggest that the vague symptoms reported by some Gulf veterans may result from genuine illnesses caused by exposure to chemicals. The findings are at odds with the main conclusion of a blue-ribbon panel commissioned by the White House, which yesterday issued a report saying that stress probably explains many vets' symptoms.

"Yes, there is a Gulf War syndrome. In fact, there appear to be several," says George Lundberg, editor of the Journal of the American Medical Association (JAMA), which is publishing the studies in its 15 January issue. But that assertion will likely be extremely controversial.

Three studies led by epidemiologist Robert Haley of the University of Texas Southwestern Medical School in Dallas examined the health complaints of 249 Navy reservists who served in the Gulf. The researchers found that 63 (25%) reported neurological symptoms that could be sorted into three clusters: memory and sleep problems; reasoning problems, confusion and dizziness; and muscle pains and fatigue. The researchers found that these three "syndromes" correlated with the soldiers' recollections that they had experienced side effects from an anti-nerve gas agent--pyridostigmine bromide, or PB--and/or had been exposed to pesticides and, possibly, chemical weapons. The Texas team also performed neurological tests such as magnetic resonance imaging scans and tests of nerve-signal speed on 23 vets who reported these symptoms and found that, compared with 20 healthy vets, they had significantly more neurological damage.

The researchers say these syndromes are consistent with a rare neurological disorder, called delayed neuropathy, seen in people poisoned with organophosphate pesticides. And they note that a study they co-authored last spring showed that, at high doses, cocktails of PB and two pesticides used in the Gulf caused nerve damage in chickens. "We've taken the breakthrough step" toward explaining some vets' illness, Haley claims.

But some experts say the JAMA studies must be viewed with caution. The Texas team's results involved a single reserve unit whose members volunteered for the study, and only a few were actually tested for disease, says White House panel member Philip Landrigan of Mount Sinai School of Medicine in New York. That casts doubt on whether the results would apply generally to sick Gulf War vets, he says. Epidemiologist John Bailar of the University of Chicago is even more skeptical: "Many people have come up with plausible hypotheses that failed under further study, and I think it is way premature to get excited about this one."